Dag Odenhall dag.odenh...@gmail.com writes:
I particularly like she's (her?) syntax for Alternative. Not sure
whether or not Idris has that. Applicative tuples would be nice too,
something like (|a,b,c|) translating to liftA3 (,,) a b c. And
operators too, liftA2 (+) a b as (| a + b |)?
I
On Thu, Aug 15, 2013 at 5:39 AM, Jason Dagit dag...@gmail.com wrote:
Also, if anyone wants to look at prior art first, Idris supports applicative
brackets.
As does she [0].
Erik
[0] https://personal.cis.strath.ac.uk/conor.mcbride/pub/she/idiom.html
I particularly like she's (her?) syntax for Alternative. Not sure whether
or not Idris has that. Applicative tuples would be nice too, something like
(|a,b,c|) translating to liftA3 (,,) a b c. And operators too, liftA2 (+) a
b as (| a + b |)?
On Thu, Aug 15, 2013 at 11:08 AM, Erik Hesselink
Simon Peyton-Jones simo...@microsoft.com writes:
| Indeed, I wished the 0-ary case would be more alike to the unary
| and binary case, cf.
|
| return f0
| f1 $ a1
| f2 $ a1 * a2
|
| What is needed is a nice syntax for idiom brackets.
Indeed. I'm quite open to adding
If we're adding applicative brackets, it would be nice to have something
like ⦇⦈ as options via UnicodeSyntax. When playing around with She, I found
it much easier to read than the ASCII version, especially when I needed to
combine them:
(|(|a + b|) + (|c * d|)|)
⦇⦇a + b⦈ + ⦇c * d⦈⦈
On 13/08/13 17:38, Andreas Abel wrote:
Indeed, I wished the 0-ary case would be more alike to the unary and binary
case, cf.
return f0
f1 $ a1
f2 $ a1 * a2
You could always write the above as
pure f0
pure f1 * a1
pure f2 * a1 * a2
Twan
| Indeed, I wished the 0-ary case would be more alike to the unary and
| binary case, cf.
|
| return f0
| f1 $ a1
| f2 $ a1 * a2
|
| What is needed is a nice syntax for idiom brackets.
Indeed. I'm quite open to adding idiom brackets to GHC, if everyone can agree
on their
On Wed, Aug 14, 2013 at 7:54 PM, Simon Peyton-Jones
simo...@microsoft.comwrote:
| Indeed, I wished the 0-ary case would be more alike to the unary and
| binary case, cf.
|
| return f0
| f1 $ a1
| f2 $ a1 * a2
|
| What is needed is a nice syntax for idiom brackets.
Indeed.
On 06.08.2013 10:46, Adam Gundry wrote:
On 06/08/13 06:14, J. Stutterheim wrote:
Suppose we now have the opportunity to change the name of the
`return` function in Monad, what would be a better name for it?
(for some definition of better)
Rather than proposing a different name, I'm going to
On Thu, Aug 8, 2013 at 7:40 AM, Timon Gehr timon.g...@gmx.ch wrote:
You make the distinction between evaluate,
Which essentially means applying reduction rules to an expression until
the result is a value.
and execute or run, etc. This is not functional.
How would you know?
I think
On Thu, Aug 08, 2013 at 01:19:27AM +0200, Jerzy Karczmarczuk wrote:
Bardur Arantsson comments the comment of Joe Quinn:
On 8/7/2013 11:00 AM, David Thomas wrote:
twice :: IO () - IO ()
twice x = x x
I would call that evaluating x twice (incidentally creating two
separate evaluations of
On 7/08/2013, at 2:10 PM, damodar kulkarni wrote:
I bet you can find an abundance of C programmers who think that
strcmp is an intuitive name for string comparison (rather than compression,
say).
But at least, 'strcmp' is not a common English language term, to have
acquired some
Richard A. O'Keefe :
Haskell has*trained* my intuition to
see 'putStrLn Hi' as a pure value; it's not the thing itself that has effects,
but its interpretation by an outer engine, just as my magnetic card key has by
itself no power to open doors, but the magnetic reader that looks at the card
One of the surprising things of Haskell is how little effort is done in
order to confer meaning to the names. That happens also in the case of the
mathematical language. Often they have a single letter. The reason is that
their meaning is completely defined by their signature and their
properties.
Fine reasoning.
Pure means incorruptible. It means that a pure result can be reused again
and again -like the gold or silver- while an impure result must be
re-created whenever it must be used. The metaphor is natural and I guess
that the use of pure (rather than referential transparent) is
It is intuitive has no other discernable meaning than *I* am familiar
with it, or something very much like it.
Thanks for pointing this out, I was not able to point my thoughts in this
direction.
But I still have a doubt: if my familiarity doesn't come in the form of
some analogy, then my
quoth Richard A. O'Keefe,
...
If you're familiar with *English* rather than, say, the C family of
programming languages, return isn't _that_ bad, there is certainly
nothing about the word that suggests providing a value.
The RFC822 headers of your email suggest that you use a Macintosh
2. This is the only way you can evaluate your pure value, and because of
the monadic chaining, you cannot do it twice, you cannot re-evaluate it.
I'm sure there is a sense in which this is true, but I'm not seeing it.
How would you describe what's going on here?
twice :: IO () - IO ()
twice x
Return is all about providing a value *when used transitively*. When used
intransitively, it's about moving yourself. There's nothing about the
latter sense that implies providing a value.
Which is not to say Richard did not overstate the case - return needn't
necessarily (in English) suggest
On 8/7/2013 11:00 AM, David Thomas wrote:
twice :: IO () - IO ()
twice x = x x
I would call that evaluating x twice (incidentally creating two
separate evaluations of one pure action description), but I'd like to
better see your perspective here.
x is only evaluated once, but /executed/
On 2013-08-07 22:38, Joe Quinn wrote:
On 8/7/2013 11:00 AM, David Thomas wrote:
twice :: IO () - IO ()
twice x = x x
I would call that evaluating x twice (incidentally creating two
separate evaluations of one pure action description), but I'd like to
better see your perspective here.
x
Bardur Arantsson comments the comment of Joe Quinn:
On 8/7/2013 11:00 AM, David Thomas wrote:
twice :: IO () - IO ()
twice x = x x
I would call that evaluating x twice (incidentally creating two
separate evaluations of one pure action description), but I'd like to
better see your perspective
On 7/08/2013, at 9:17 PM, Jerzy Karczmarczuk wrote:
I am the last here who would quarrel with Richard O'K., but I firmly believe
that such reasoning is a Pandora box.
The King, the government, the Pope, etc. have no power, only the
interpretation of their decrees by outer agents _does_
On 8/08/2013, at 2:09 AM, damodar kulkarni wrote:
Thanks for pointing this out, I was not able to point my thoughts in this
direction.
But I still have a doubt: if my familiarity doesn't come in the form of some
analogy, then my acquired intuition about it would be of little use. In
On 08/08/2013 01:19 AM, Jerzy Karczmarczuk wrote:
Bardur Arantsson comments the comment of Joe Quinn:
On 8/7/2013 11:00 AM, David Thomas wrote:
twice :: IO () - IO ()
twice x = x x
I would call that evaluating x twice (incidentally creating two
separate evaluations of one pure action
On 8/08/2013, at 2:56 AM, Donn Cave wrote:
The RFC822 headers of your email suggest that you use a Macintosh computer,
so apart from the apparently disputable question of whether you're familiar
with English, you have the same online dictionary as mine.
My department has an electronic
quoth Richard A. O'Keefe
Check the OED. Most of its meaning are about _turning back_,
_resuming_, _reverting_. Yielding or making a profit is not at
all about providing a value, but about money going out AND
COMING BACK. It's the coming back part that makes it a return.
Yes. Return means
next, carry, feed, roll
On 6 August 2013 08:37, KC kc1...@gmail.com wrote:
I thought a pure value was being returned from the monad. :)
On Mon, Aug 5, 2013 at 10:32 PM, Christian Sternagel
c.sterna...@gmail.com wrote:
Dear Jurriën.
personally, I like lift (which is of course already
Thanks Chris. Yes, I like lift as well, because I find it a rather intuitive
name. Unfortunately, as you say, it is already a commonly used name as well,
which might make it slightly confusing.
When I hear `unit` I immediately think about generic programming, not so much
about monads. Can you
Hi Tarik,
Could you motivate the choice for these names? Thanks!
On 6 Aug 2013, at 08:14, Tarik ÖZKANLI tozkanli2...@gmail.com wrote:
next, carry, feed, roll
On 6 August 2013 08:37, KC kc1...@gmail.com wrote:
I thought a pure value was being returned from the monad. :)
On Mon, Aug
What about `pure`? It's already used in applicative, and has the
motivation that it's embedding a pure value in some context. Since I
don't know the details of your project, I don't know if you need two
names (one for the applicative version, and one for the monadic
version).
Erik
On Tue, Aug 6,
I have to admit that I am a bit torn about using `pure`. On the one hand, if
you actually have a pure value, it feels pretty intuitive to me. But what about
pure (putStrLn Hi)
`putStrLn Hi` is not a pure value... Or is there another way to interpret the
word pure in this context?
As for
What about 'pack'?
Best,
Karol
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
What about 'inject'?
On 6 August 2013 09:09, Karol Samborski edv.ka...@gmail.com wrote:
What about 'pack'?
Best,
Karol
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
On Tue, Aug 06, 2013 at 10:03:04AM +0200, J. Stutterheim wrote:
`putStrLn Hi` is not a pure value...
Why not?
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
It is a pure value in the context of the outer monad (the one you wrap it
in). I'd say pure is still appropriate.
On Aug 6, 2013 10:14 AM, Tom Ellis
tom-lists-haskell-cafe-2...@jaguarpaw.co.uk wrote:
On Tue, Aug 06, 2013 at 10:03:04AM +0200, J. Stutterheim wrote:
`putStrLn Hi` is not a pure
What about promote ?
On Tue, Aug 6, 2013 at 6:15 PM, Tom Ellis
tom-lists-haskell-cafe-2...@jaguarpaw.co.uk wrote:
On Tue, Aug 06, 2013 at 10:03:04AM +0200, J. Stutterheim wrote:
`putStrLn Hi` is not a pure value...
Why not?
___
Haskell-Cafe
On 08/06/2013 04:30 PM, J. Stutterheim wrote:
Thanks Chris. Yes, I like lift as well, because I find it a rather intuitive
name. Unfortunately, as you say, it is already a commonly used name as well,
which might make it slightly confusing.
When I hear `unit` I immediately think about generic
What about X, Y, Z, ...
We have seen this discussion already a long time ago. The terms unit
and result have been proposed. And others. Somebody (I forgot who)
advocated even the name monad in this context. And this might have
continued forever...
With all my respect, I see that Haskell
Hi,
On 06/08/13 06:14, J. Stutterheim wrote:
Suppose we now have the opportunity to change the name of the
`return` function in Monad, what would be a better name for it?
(for some definition of better)
Rather than proposing a different name, I'm going to challenge the
premise of your
Hi Adam,
Thank you for an interesting thought; an invisible name might actually be on of
the better solutions, although you are right in that your suggestion is a bit
too open for my current project.
Actually, I believe that naming is very important. My goal is to have the
average programmer
That argument makes sense, although I find it a bit counter-intuitive still. If
I saw the function `pure` for the first time, my first impression (however
wrong it may be) would be that it takes a pure value (regardless of context)
and does something with it. Applying `pure` to an IO operation
Le 06/08/2013 11:01, J. Stutterheim a écrit :
... So in reply to Jerzy, I do want to encourage the discussion in the Noble Domain
of Philosophy and I also want to repeat that I am not proposing to change Haskell
or Haskell libraries
Jurriën, I taught Haskell for several years. I saw the
that may somehow fit into
1 and 2:
3) eval = Control.Exception.evaluate :: a - IO a
regards
- marc
Gesendet: Dienstag, 06. August 2013 um 11:43 Uhr
Von: Jerzy Karczmarczuk jerzy.karczmarc...@unicaen.fr
An: haskell-cafe@haskell.org
Betreff: Re: [Haskell-cafe] Alternative name for return
But IO actions *are* pure values. What side effects do they have? None! You
can do whatever you want with them with no harmful effects in any Haskell
expression. They only special thing about them is that they have a run
function that is not itself provided in Haskell. The run function is
actually
On Tue, Aug 6, 2013 at 4:03 AM, J. Stutterheim j.stutterh...@me.com wrote:
I have to admit that I am a bit torn about using `pure`. On the one hand,
if you actually have a pure value, it feels pretty intuitive to me. But
what about
pure (putStrLn Hi)
`putStrLn Hi` is not a pure value...
Le 06/08/2013 14:47, Jake McArthur a écrit :
... But IO actions *are* pure values. What side effects do they have?
None! /You can do whatever you want with them/ with no harmful effects
in any Haskell expression. They only special thing about them is that
they have a run function
As I said,
On Tue, Aug 06, 2013 at 04:26:05PM +0200, Jerzy Karczmarczuk wrote:
1. First, it is not true that you can do with, say, (printStr Ho!
) whatever you want. In fact, you can do almost nothing with it. You
can transport it as such, and you can use it as the argument of
(=).
I don't think this
On 13-08-06 01:14 AM, J. Stutterheim wrote:
N.B. I am _not_ proposing that we actually change the name of `return`. I do
currently have the opportunity to pick names for common functions in a
non-Haskell related project, so I was wondering if there perhaps is a better
name for `return`.
I
Bikeshedding at its finest. I think if we are very lucky, then a long time
from now we will be able to deprecate return in favor of
Control.Applicative.pure
As for making it invisible, that's what idiom brackets and monad
comprehensions are for. But for those creating an *instance* of Monad,
On 6/08/2013, at 9:28 PM, J. Stutterheim wrote:
That argument makes sense, although I find it a bit counter-intuitive still.
In discussions like this, I have never been able to discover any meaning for
intuitive other than familiar. Applying pure to an IO operation doesn't
go against *my*
I bet you can find an abundance of C programmers who think that
strcmp is an intuitive name for string comparison (rather than
compression, say).
But at least, 'strcmp' is not a common English language term, to have
acquired some unintentional 'intuition' by being familiar with it even in
On Tue, Aug 6, 2013 at 9:10 PM, Richard A. O'Keefe o...@cs.otago.ac.nzwrote:
I bet you can find an abundance of C programmers who think that
strcmp is an intuitive name for string comparison (rather than
compression, say).
Them and a small and slowly shrinking group of folks who find it
Dear Jurriën.
personally, I like lift (which is of course already occupied in
Haskell), since an arbitrary value is lifted into a monad. (The
literature sometimes uses unit.)
cheers
chris
On 08/06/2013 02:14 PM, J. Stutterheim wrote:
Dear Cafe,
Suppose we now have the opportunity to
I thought a pure value was being returned from the monad. :)
On Mon, Aug 5, 2013 at 10:32 PM, Christian Sternagel
c.sterna...@gmail.comwrote:
Dear Jurriën.
personally, I like lift (which is of course already occupied in
Haskell), since an arbitrary value is lifted into a monad. (The
55 matches
Mail list logo
